<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <link rel="stylesheet" href="./bootstrap-4.6.2/css/bootstrap.min.css">
  </head>
  <body>
    <button class="btn btn-primary" id="sync">同步</button>
    <script src="./jquery-3.7.1.min.js"></script>
    <script src="./bootstrap-4.6.2/js/bootstrap.min.js"></script>
    <script src="./popup.js"></script>
  </body>
</html>